1. Field of the Invention
This invention relates to an image processing apparatus, and more specifically relates to an image processing apparatus which can modulate image data arbitrarily.
2. Related Background Art
Processing of input pixel data for density modulation using an arbitrary pattern has hitherto been performed using a costly printer or by means of computer processing, etc. (such processing is hereinafter referred to generically as "texture processing").
FIGS. 3A through 3C illustrate texture processing in which an image shown in FIG. 3A is modulated by a pattern shown in FIG. 3B to obtain an output image shown in FIG. 3C.
However, an image processing apparatus capable of performing texture processing in real time to output an image has not been available.
Texture processing also suffers from a problem in that it is affected by the density of the read pattern, i.e., the density of the whole output image is lightened when modulation by a pattern lighter than the image being modulated is performed, and is darkened when modulation by a darker pattern is performed.
Such texture processing is disclosed in U.S. Pat. No. 5,021,876 assigned in common with the present application.